Gate brick



Nov. 1s, 1958 J, M MCgRACKEN 2,860,392

GATE BRICK Filed Deo. 8, 1955 J INVENTOR. L36 36 Fl g 6 James M.McCracken A l BY @M/Mv M5 H/s ATTORNEYS United States-Patent' Thisinvention relates generally to'sand molds of the type having a moldcavity, a vertically directed sprue,

and a gate connecting the mold cavity and sprue, and

more particularly relates to a novel form of gate brick which forms thegate between the cavity and the sprue.

In one form of sand casting procedure, molten metal is poured verticallydownwardly through a sprue and then ilows laterally through a gate andenters into a mold cavity formed in the sand. Despite the extent towhich the sand is rammed and compacted prior to metal pouring, the sandsometimes lacks the firmness with which to withstand the forces of thestream of metal at the point of turning laterally from the sprue and themetal tends to wash away the sand beyond or at this point or in bothplaces. More permanent bodies such as refractory gate bricks have beenproposed as a substitute for sand at these places to withstand theabrading and loosening effect of the right-angled turning of the streamof metal as it pours into the cavity, but these gate bricks arenecessarily unsupported and exposed along an entire side adjacent andfacing the mold cavity and in some cases they may have a disadvantageoustendency to topple into the cavity or else loosen during one stage ofshock due to the direct contact with the molten stream of metal beingpoured.

Due to its novel form the present gate brick materially reduces orlargely eliminates the foregoing disadvantages and, as a result of itsimproved key-hole shape as viewed in outline from the top or bottom ithas positive provision for locking the same in place in a mold toprevent dislocation toward or lateral dislodgement of the brick into themold cavity. My gate brick, moreover, provides a downwardly directedramp for directing flow which slopes toward the mold cavity at a readilyapparent angle of depression below the horizontal and therefore no sandcoating suspension poured down the sprue onto the ramp tends to stand orcollect in a pool but runs off the surface thereof.

Further features, objects and advantages will hereby be specificallypointed out or become apparent when for a better understanding of theinvention, reference is made to the following description taken inconjunction with the accompanying drawings in which:

Figure l is a vertical longitudinal section through a sand moldembodying the present gate brick invention,

Figure 2 is a horizontal section in top plan view taken along thesection line II--II of Figure 1,

Patented Nov. 1,8, 1958 ricc Figure 3 is a perspective view of the gatebrick,

Figures 4, 5, 6 are top plan, front face, and side elevational viewsrespectively of the gate brick with certain portions in Figure 6 brokenaway for the sake of clarity.

In particular in the drawing, Figures 1-6 show a sand mold 10 havingconventional flask 12 and a pair of base or stool plates 14 and 16supporting the llask and the mold. A conventional type of core barrel 18carries a portion20 of a body 22 of molding sand. The portion 20constitutes the inner core of the mold. The remainder 22 of the body ofsandhas an upright sprue 24 formed therein and cooperates with the innercore 20 to define an included mold cavity 26. The particular cavityshown at 26 is for the production of ingot molds although it is to be'understood that the present invention is applicable to molds generally.The sprue 24 carries a pouring funnel 28 at the upper end thereofthrough which molten metal is introduced into the sprue. From the sprue24 the downwardly owing stream of metal passes through a gate brick 30of refractory material and in so doing turns laterally inwardly to passthrough a gate opening 32 into the mold cavity 26. The techniqueemployed is more commonly referred to as bottom pouring in view of thefact that the molten metal is introduced adjacent the ,bottom of themold cavity 26.

'Ihe gate brick 30 has a Hat top surface 34, a flat bot-- tom surface 36and a flat front surface 38 which is vertically disposed between the twoand in which the generally vertically oblong gate opening 32 is formed.The opening 32 registers with the interior of a rectangularly shapedhollow body portion 40 of the brick having parallel vertically disposedopposite cheeks 42. The brick 3i) has a generally cylindrical rearportion 44 formed with a cylindrical vertical passageway 46 termed adowncomer and communicating directly at its upper end with the sprue 24in the mold. The passage 46 communicates at the other end with the gateopening 32 and the mold cavity 26 through the hollow interior of thebody portion 40.

The hollow interior of the body portion 40 has a sloping bottom or oor48 which forms an angle of approximately 82 with the plane of thevertical front face 32 and which in the particular position of Figure 6slopes` downwardly and to the left at an angle of approximately 8 fromthe horizontal. The top o r ceiling 50 of the hollow interior has asimilar downward slope although the presence of a slope in the latter isnot essential to the present invention.

In one physically constructed embodiment the invene` tion was key-holeshaped as viewed in outline from the; top with the outside diameter ofthe rear portion 44 ofi the brick 30 approximately 25% greater than thewidth; of the hollow body portion 40 as measured by the trans-- versedistance between its opposite cheeks 42. There,-- fore, at the resultingjuncture at 52 between body portion and the cylindrical rear portion 44the latter extended laterally in both opposite directions beyond thestraight cheeks 42 with the result that the rammed sand portion 22,Figure l takes a corresponding keyhole shape as viewed in outline(Figure 2) causing the gate brick 30 to be locked in place in the mold.r[hat is to say, the sides of the cylindrical portion 44 bulge into thesand at the rear of the brick 30 and thus form widened shoulders,preventing the brick 30 from toppling face forward intoY the mold cavity26 even when the walls of the cavity incline inwardly as shown inFigure 1. It is to be noted that the hollow interior of the body portion40 of the;v brick tapers and narrows as it approaches the oblonggateopening 32.

In operation following ramming of the sand into the mold at 22 and 20within the flask 10, a water suspension of carbon blacking or graphiteis used to paint the wallen of the mold cavity 26 and another portion ofthe suspension is poured down the funnel 28 and sprue 24 and thereafterthe whole assembly is dried. Due to the sloping floor 48 ofthezhollowinteriorof. therfrefractory brick 30, noblacking tendsito. collect. in.a poolftherein,

but is ,discharged.,inwardly,/ towards the mold cavity. 26m

Then following. drying. and assemblyV of-the,moldiwit h the core 18andstool ,plate 16, moltenmetaljs poured-down the, funneland sprue 28,24a11d;,isdischarged.,throughv thelocked-in refractory gate` brick 30`into the; mold.

cavity; 26. Regardlessof whether,v orxnot the mold is driedl suiciently,to` eliminate allrmoisture therefrom,

thereisno possibilityof blackingbeing; present.y .and.co1

lectingin the downcomer passage146 .oriupongtheoor 48, which if Vpresentwouldbe likely torcauseian;explosion.v

wh er1 ,mo1ten` metal is subsequently` pouredy down the sprue 2 4.

Pouringis continued until, in. conventional.bottom.

pourfashion, Ithemold cavity 2,6andthesprue24 are.

completely lled with metal whereupon the metal is allowed to cool andsolidify to form the-,desired metal.- casting, .being an ingot mold inthe caseillustrated. The casting is removed from the mold,thexadheringvrsand. is.

removed from the casting, and nally the .excess metal and waste pieceswhich were present in the sprue and gate brick and elsewhere are.chipped away from .the casting.

Chipping away the waste metal at the juncture defined Variations withinthe spirit and scope of the invention described are equally comprehendedby the foregoing description.

I claim:

In a bottom-pour sand mold having a gate brick at the bottom forestablishing,communication laterally between a vertical sprue and themold cavity, a one-piece refractory gate brick of' generally keyholeshape as viewed in outline from the top to fit in a correspondinglykey-hole shaped void formed thereby in the sand mold material, saidbrick having a block-like hollow body portion with a front face arrangedto form part of a major wall in the mold cavity, a vertically oblonggate opening formed in said face for connecting the mold'cavity with thehollow interior of said block-likebodyfportiom and a cylindrical portionjoined to the rear of the block-like body portion in a manner tocomplete said general key-hole shape and defininga verticalpassagecommunicatively connected to said hollow interior of the latter portionto form substantially a right-angled intersection therewith, saidblocklike body and cylindrical portions mutually defining a passage oorof generally key-hole shape in outline and generally sloping at leastapproximately 8 from the horizontaltowardisaidgateopeningLsaidcylindricalrear portion, having an1; outside diametrical ,widthat leastapproximately 25% greaterl than: the'. sidewise-v spanbetweenibothcheeks of theVV block-likeY body 'portion solas tobulgefvinto said void for locking the brick laterally against falling.face-forward into the mold cavity.

References Cited invtheiile of thispatent UNITED STATES PATENTS 581,017'Bryant Apr. 20, 1897 694,315 Carroll Feb. 25, 1902 1,042,092 Custer Oct.22, 1912 1,103,039 Cudell July 14, 1914 1,614,360 Granade Jan. 11, 19271,657,952 Zoda Jan. 31, 1928 1,779,763 Carter et al. Oct. 28, 19301,817,340 Barr Aug. 4, 1931 1,891,867 Burdick et al. Dec. 20, 19322,459,025 Graham Jan. l1, 1949 FOREIGN PATENTS 439,526 Great BritainDec. 9, 1935 l

